Chapter 7.4, Problem 4CP

Interpretation Introduction

Interpretation:

The first and second ionization energies (${\text{IE}}_{\text{1}}$ and ${\text{IE}}_{\text{2}}$) and electron affinity (${\text{EA}}_{\text{1}}$)for the given elements are to be compared.

Concept introduction:

Ionization energy ($\text{IE}$) is the minimum energy required to remove an electron from an atom in the gaseous phase.

The first ionization energy (${\text{IE}}_{\text{1}}$) corresponds to the removal of the most loosely held electron.

The second ionization energy (${\text{IE}}_{\text{2}}$) corresponds to the removal of the second most loosely held electron.

Effective nuclear charge increases from going left to right in a period (increasing $\text{IE}$), and it is more difficult to remove a paired core electron than an unpaired valence electron.

Electron affinity ($\text{EA}$) is the energy released when an atom in the gaseous phase accepts an electron. $\text{EA}$ increases from going left to right across a period(with exceptions of groups $2\text{A}$ and $\text{5A}$).